The abrasive products with a non-woven base are totally known. Many of the commercially available products are made of a web of non-woven synthetic fibers to which hard abrasives finely divided such as silica carbide, alumina and silica, are added. Other soft abrasives include calcium carbonate, talc, and synthetic polymer resins. In repeated occasions, as an example of such fibers the previous art mentions, the one commercialized under the “Scotchbrite” and “Buf Puf” brand from Minnesota Mining and Manufacturing Co, which contains aluminum-oxide particles in a way that abrasive power is reinforced.
It has been widely recognized that in many cleaning applications, specially in home applications, housewives or users of the said abrasive item, discard it when the bad odor is evident and constant, even when the item maintains its abrasive properties. As a consequence, there is an excessive expenditure when replacing abrasive items, as well as a waste of useful material.
An alternative to avoid such situation is to incorporate perfume or fragrance to the cleaning items, for example, to those designed for toilets and kitchens in order to provide a fresh aroma or scent to the treated surfaces and to the surrounding environment, but problems have been found to achieve this.
The previous art describes some intents for aromatizing cleaning articles, such as the described in the British Patent GB 1,374,272 (Bayliff A., Geoffrey, 1974) regarding the impregnation of cleaning pads, stating that the fabric is saturated with perfume, with the inherent problems of personnel discomfort or contamination of other products manufactured in the same facilities, or, the fact that a perfume appropriate for a toilet might not be acceptable for other products. Another problem is the storage of the aromatized product along with other products, and that the package is not hermetic. Another problem is the waste of perfume due to evaporation when the product is manufactured and stored.
Therefore, an important feature of such products is their ability to extend their performance for a long period of time while retaining certain amounts of the functional ingredients (perfumes) while only a portion of such ingredients is exposed to the surrounding environment. The control of the release ratio can be achieved in a variety of manners, including diffusion by means of the voids in the web, forcing the ingredient to the surface by compressing the voids and breaking the spheres or internal cells of the matrix of the support material. A solution described in this patent is to include fragile capsules, of a very small size and filled with perfume, that can be incorporated to the filler of a cleaning pad; an alternative mode is to use capsules with water soluble walls, which dissolve precisely when pad gets wet for its use. It is suggested that the perfume is oily or oil-based. The pad fabric can be pulp, crepe fabric or non woven waste material; the capsules can be spread in the filler material by means of an adhesive or by means of printing, as a viscous mixture or in an appropriate diluter or even as an effervescent tablet.
U.S. Pat. No. 4,514,461 (Yen-Kong Woo, 1985) describes a cloth saturated with microscopic spheres in the form of fragile capsules, inside the voids of the internal fibers of the cloth fabric, that can be woven or non woven, in such a manner that the spheres remain in the cloth and can be invisible in its surface so the appearance is not altered. The cloths described in the latter patent include, cotton, wool, silk and other synthetic cloths.
The process used to emboss the microparticles in the cloth is made of three stages: a) spraying or saturating the cloth with the capsule solution into an adhesive such as acrylic latex; b) rolling between two hot rollers with the same pressure and temperature to ensure a deep and consistent penetration and to remove the particles in the surface and c) adhesive curing.
U.S. Pat. No. 4,882,220 y U.S. Pat. No. 4,917,920 (Ono, Akira et al, 1989, 1990) describe an aromatic fibrous structure, made of cloth or a similar material, with microcapsules containing perfume; the microcapsules are made of an external wall with a formaldehyde based resin from the urea-formaldehyde resin and melamine-formaldehyde type. The microcapsules are bonded to a fibrous base of 0.7 denier or less which hold the microcapsules in the voids of the fibrous structure.
The manufacturing process of the fabric is described in patent '920, and includes the application of a liquid containing microcapsules made of a formaldehyde-based resin wall, an aromatic substance and a prepolymer substance of thermally reactive organopolysyloxane, and a drying process for the fibrous structure with a temperature below 150° C., to bond the microcapsules.
The description of the previous art of the said patents makes a very thorough review of the intents for applying an aromatic substance to what they call a “closed system” (encapsulating in microcapsules) to a fibrous structure, and then converting the closed system into an “open system” by breaking the microcapsules by means of efforts applied to the microcapsules in order to release the fragrance during the fibrous structure use. The following is mentioned as previous art: an application method for a mixture of microcapsules containing a liquid for toilets with a coating of adhesive containing a melamine resin, a cloth (British patent 1,401,143); an adhesion method for the microcapsules containing perfume, with the aid of a capsule remover mainly containing a cationic organic substance such as ammonia quaternaries or similar substances and a non-ionic organic substance such as esters or sorbitan or similar substances (Japanese application 52-31,200); a method to prepare aromatic towels by applying a liquid mixture of microcapsules containing perfume with an acrylic resin, cloth for towels (Japanese patent application 58-4,886); a method to prepare fragrance releasing printed cloth by printing a paste made of thermoplastic material, a thickening agent and microcapsules containing perfume (Japanese patent application 53-47,440 y 53-49,200); a method to prepare printed cloth that release a fragrance by thermal transference of an adhesive layer made by a pigment, a high molecular weight resin, perfume microcapsules, etc. to a cloth (Japanese application 53-106, 885).
All of these methods offer a poor bond that results in a low washing resistance. The use of high temperatures, even when bonding is improved, results in problems such as denaturalization of the perfume, or microcapsule collapsing due to perfume vaporization occurring due to high temperature.
There is an emphasis on the fact that nylon fibers, due to their smoothness, make appropriate bonding difficult.
The active ingredient release from the microcapsules, can be achieved by diffusion, volatilization, pressure or stirring. The release can be gradual when simple diffusion or volatilization are involved, or, on demand, when pressure, stirring or a combination of techniques are involved. The particles themselves can be rigid or compressible. The encapsulated substance tends to be fluid, including volatile and non-volatile liquids or solutions, a soluble solvent or a solid with a low fusion point or a semi-solid. The release on demand can be achieved, depending on the product features by:    a) An external mechanical effort, pressure or rubbing of the article on a surface for which the active substance intended,    b) Wall fusion, by heat application, for example, on such articles intended to be used near the human body,    c) Dissolution in the media in which they are added, due to the contact with a solvent, body parts or other liquids.
The use of particles (spheres or microcapsules) as a mechanism to retain the active substances, provides a better control on their release than the systems where the fiber matrix is directly impregnated with the substances, as described above in the reference to patent GB 1,374,272.
When the release is controlled, it occurs in a more sustained manner giving a continuous and fresh supply to the fiber matrix and to the environment in which the matrix is placed or to the surface with which it has contact.
Finally, it is important to say that the documents mentioned up to this point and that are regarded as previous art, the incorporation of microcapsules with active ingredients such as perfume and fiber matrix support, are limited to woven and non-woven cloth, intended to manufacture clothing or similar products, but there are no references of fiber matrixes of a higher thickness, intended for abrasion, scouring and cleaning, which is the objective of the present invention.
There are, however, some references that indicate the obvious interest of incorporating a series of improvements to the cleaning and abrasive item properties to use microcapsules of active ingredients other than perfume, or, the use of fragrances as a value added to the primary function of the articles:    U.S. Pat. No. 5,876,266 (Miller et al, 1999) describes a polishing pad made of semiconductor waffles, where the pad has microcapsules with a polishing agent; the release is controlled by a polishing parameter.    Patent application WO 99/51401 (Cheyne, Robert, 1999) describes an abrasive pad for domestic use, specially for kitchen and baths, with a non-woven matrix in which an antimicrobial compound is spread.    The other reference, from the site http://www.whitemop.com/catalog/24.html, shows a pad for polishing floors manufactured with natural coconut fiber, that releases a “fresh coconut” fragrance when the pad is moistened with coconut oil. The odor release occurs when the polisher is on with the pad moistened with coconut oil, which is added in a liquid form.
The information herein is deemed as representative of the state of the current techniques, and has been mentioned so a person with knowledge on the subject can establish that it does not interfere with the matter of the present invention described below.